Android Apps - Android Studio
Android Studio includes a complete development toolkit for creating Android apps. Similar to Apple's XCode, Android Studio includes programming languages, version management, access to a device library, and a simulator. With the current copy of Android Studio, a Java runtime license is included, so its not necessary to download one from the Java website. Kotlin is now recommended by Google for Android app development and is included with Android Studio. Kotlin is an open-source programming language which is similar to Java.
The Java language was developed by Sun Microsystems, which Oracle purchased in 2009. In previous versions of Android development tools, it was necessary for the developer to obtain a Java download and license from Oracle in order to develop Android apps. Even though the Java license is free, Google is promoting and supporting Kotlin as a development language for new apps so developers don't have to worry about any licensing changes that Oracle might make in the future.